Adjustable weight putter

ABSTRACT

An adjustable weight golf putter is provided with a body portion of a material of low specific gravity, for example aluminum, and a weighted cap, receivable in a longitudinal recess opening at the back extremity of the body portion. The weighted cap is formed of a material of high specific gravity, for example a tungsten-copper alloy, and has a weight which is at least more than 20%, and preferably more than 30% of the weight of the lighter body portion, concentrating the weight of the putter head toward the back and locating its center of gravity more than half way toward the back of the putter head. The weighted cap is secured by a threaded shaft engageable in a recess extension in the body. Optional weighted discs, of a high specific gravity material and each of a different weight, are threadedly engageable with the shaft and are usable in various combinations for optimal weight adjustment. The optional weights are applied in tight engagement with the weighted cap, to maintain weight concentration at the back.

BACKGROUND OF THE INVENTION

The present invention relates to golf putters and more specifically toan improved form of putter head incorporating novel and advantageousmeans for concentrating weight near the back end of the putter, spacedwell behind the ball-striking face, and also providing for an improved,simplified and effective arrangement for adjustably weighting the putterhead to enable the putter to be optimized to the desires and abilitiesof the golfer.

There are numerous examples in the prior art of putters incorporatingfeatures providing for adjustable weighting of the putter head. TheBushner U.S. Pat. No. 4,895,371, for example, discloses a putter headhaving one or more bores therein for receiving a rod, on which a weightis slideably mounted and secured in position by a set screw. The rod iscontained within the putter head by means of a threaded plug.

The D'Eath U.S. Pat. No. 5,046,740 discloses a putter head in which alongitudinal cavity in the putter is filled with steel balls, in orderto increase the weight of the putter along its center line.

Other prior art concepts involve the placement of one or more weightedelements at various locations on the putter head to enable the golfer tovary the weight to suit his desires and/or abilities. Many of theseknown concepts are largely unsuccessful as commercial products, eitherbecause they are complicated to work with, because they place the weightadjustment elements at locations that do not optimize the weight balanceof the putter, and for other reasons.

SUMMARY OF THE INVENTION

The present invention provides an adjustable weight putter head which iseasy to use and which, to the greatest practical extent, optimizes theweight balance of the putter by concentrating weight at the backextremity of the putter head, along the center line axis of the putterhead. In accordance with the present invention, a putter head isprovided in which the body is elongated in the ball-striking directionand is provided with a body cavity, at the back end extremity of theputter head, for the reception of an adjustable weighting assembly. Themain body of the putter is formed of a lightweight material, typicallyaluminum but certain engineering plastics, such as Celcon, are suitable.

In accordance with one aspect of the invention, a weighted cap,positioned at the back end extremity of the putter body, is formed of ahigh specific gravity material in relation to the material of the putterbody itself. The weighted cap forms a substantial part of the weight ofthe overall putter head assembly so as to provide a maximizedconcentration of weight at a location as far behind the putter face aspracticable. In this respect, the weighted cap advantageously has aweight which is more than 20%, and preferably more than one third theweight of the main putter head. In addition, the weighted capincorporates a threaded shaft extending forwardly therefrom which canreceive one or more of a plurality of disc-like weights, also formed ofa high specific gravity material. Preferably, each of the weights has adifferent weight, such that by mounting some or all (or none) of theweights on the threaded shaft, a wide variety of weight combinations canbe incorporated into the putter, so suit the golfer's desires.Significantly, the weights can be applied over the threaded shaft to bein abutting relation to the front face of the weighted cap, such thatthe assembly of the weighted cap and the disc-like weights concentratesthe weight mass as far back in the putter as practicable.

For a more complete understanding of the above and other features-andadvantages of the invention, reference should be made to the followingdetailed description of a preferred embodiment, and to the accompanyingdrawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a putter head according to theinvention, illustrating particularly the weighted cap and the manner inwhich disc-like weights are applied thereto.

FIG. 2 is a top plan view of the putter head of FIG. 1.

FIG. 3 is a side elevational view of the putter head.

FIG. 4 is a cross sectional view of the putter head as taken generallyon line 4-4 of FIG. 2.

FIG. 5 is an enlarged view of the weighted cap element with a disc-likeweight applied thereto.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now the drawings, the reference numeral 10 designatesgenerally a putter head which is comprised of a ball-striking face 11and an extended body portion 12 comprised of a stem 13, a body endportion 14, and gussets 15, 16 which extend along opposite sides of thestem 13 and join the ball-striking face 11 with the back portion 14 ofthe body.

Although specific dimensions of the putter head can vary, USGA rulesrequire that the length of the putter (in the ball-striking direction)be less than the width of the ball-striking face. For long-shaftedputters, it may be desired to have a larger putter head than forshort-shafted putters. In all cases, however, the length-widthrelationship specified by the USGA rules must be observed. In typicalembodiments of the invention, the face width of the putter may be around4.25 inches, for a short-shafted putter and around 5.00 inches for along-shafted putter, with the body length preferably being between 85and 90% of the width of the ball-striking face.

Preferably, the entire putter head is a one-piece molding of suitable,relatively lightweight material. Aluminum, with a specific gravity ofaround 2.65, is widely preferred by most golfers, although engineeringplastics, such as Celcon®, an acetal copolymer, available from TiconaEngineering Polymers (Division of Celanese AG) are suitable. Celcon isconsiderably lower in specific gravity than aluminum.

The illustrated embodiment will be described as if proportioned for ashort-shafted putter, it being understood that dimensions may beslightly larger for medium-shafted and long-shafted putters. However,the basic principles of the invention are not limited to specificdimensions, which as used herein are illustrative only.

In the illustrated putter head, the ball-striking face 11 preferably isrelatively thin, for example, around 0.275 inch, with a face width of,for example, 4.25 inches and face height of about one inch. The stem 13is substantially the same height as the putter face and may have atypical width of about ⅝th inch above the gussets and ⅜th inch below thegussets. The back portion 14 of the putter body comprises an arcuateupper portion 17 and a squared-off lower portion 18. The bottom surface19 of the putter is contoured in a large radius convex arc, as shown inFIGS. 3 and 4, and the bottom surface of the back portion 14 of the bodyconforms to that arcuate curvature. When the putter is in its “normal”position, as reflected in FIG. 3, the low point of the arcuate bottomsurface 19 preferably is located an inch or so behind the front of theball-striking face 11.

As reflected in FIGS. 1 and 2, the body portion of the putter headtapers from front to back, and the back extremity of the back portion isrounded and convexly contoured, as indicated at 20. The gussets 15, 16join with the back side of the ball-striking face 11 and taper in arearward direction until they merge with the back portion 14 of thebody. The front wall of 14 a of the back portion typically is spacedabout two inches behind the front face 11 (slightly less for a shortshaft putter and slightly more for a long shaft putter).

As indicated in FIG. 3 in particular, the gussets 15, 16 are relativelythin in relation to the overall thickness (height) of the putter head.By way of example, for a short-shafted putter having a thickness ofabout one inch, the gusset webs may have a thickness of about ⅛th inch.For a larger, long-shafted putter head, having an overall thickness ofabout 1.2 inch, the gusset thickness may be proportionately greater, forexample, 0.156 inch.

As shown in FIGS. 3 and 4, the gussets 15, 16 are disposed in ahorizontal plane, preferably slightly above the mid-height of the putterhead, so as to be approximately aligned with the center of a ball to bestruck. At one side of the stem 13 there is a shaft socket 21 thatextends through the gusset 16 and to, or substantially to, the bottomsurface 19 of the putter head. The shaft socket receives a putter shaft(not shown) by which the golfer handles the putter.

Pursuant to the invention, the body back portion 14 is provided with ahorizontal cylindrical recess 22, preferably extending longitudinallyalong an axis lying in the plane of the gussets 15, 16 and along thecenter of the spine 13. At the innermost end of the recess 22, there isa recess extension 23, of considerably smaller diameter, which isthreaded. The recess 22, which typically may be about ¾ quarters inch indiameter, is arranged to receive a weighted cap 24 (FIG. 5) from whichextends a threaded shaft 25. The weighted cap 24 has a cylindrical bodyportion 26, which is adapted to be closely received within thecylindrical recess 22. The threaded shaft 25 extends forward to engagethe threaded recess extension 23, which forms the means by which theweighted cap is secured within the recess 22. At its outer end, theweighted cap is formed with an outwardly divergent collar 27 adapted formating reception within an outwardly divergent portion 28 of the bodyrecess 22.

To install the weighted cap, it is inserted in the body recess 22 andits threaded shaft 25 is engaged with the threaded recess extension 23.The cap can then be rotated to be advanced into the recess, typicallywith the use of an Allen wrench engageable in a socket 29 at the end ofthe cap 24. When the divergent collar 27 seats in the divergent endportion 28 of the recess 22, the cap is positioned properly within therecess, and the recess is also sealed against the entry of moisture.Desirably, the outer end surface 30 of the weighted end cap 24 isconvexly contoured to match and smoothly continue the convex contours 20of the back of the body portion. Thus, when the weighted cap isinstalled, its presence is unobtrusive and does not detract from theaesthetics of the overall putter body.

In accordance with one aspect of the invention, the weighted cap 24 isformed of a material of much higher specific gravity than that of theremainder of the putter head. Whereas the putter head may be a one-piecemolding of aluminum, with a specific gravity of around 2.65, theweighted cap 24 preferably is formed of a tungsten-copper alloy, havinga specific gravity of about 17.06. Preferably, both the body of theweighted cap 24 and the threaded shaft are formed of the tungsten-copperalloy, although the threaded shaft could be formed of other material andfixed to the main body of the cap.

Pursuant to one aspect of the invention, the weighted cap and threadedshaft have a combined weight which is in excess of 20% of the weight ofthe other elements of the putter head, and preferably in excess of 30%of the weight of the other elements of the putter head. In all cases,the relationship of the putter head and the weighted cap is such thatthe center of gravity of the putter head, with the weighted capinstalled, lies behind the mid-way point of the longitudinal axis of theputter head, concentrating weight toward the back of the putter. By wayof example and not of limitation, a putter head for a short-shaftedputter may have an “empty” weight of around 230 grams and its cap mayhave a weight of about 95 grams. A putter head for a medium shaft puttermay have an empty weight of about 285 grams, with a cap of 65 grams. Theconsiderably larger body for a long-shafted putter may have an emptyweight of 370 grams and employ a weighted cap of 130 grams. For themedium shaft putter, which is somewhat of a hybrid design and which mayutilize a short shaft in some cases and a mid-length shaft in others,the empty weight of the body is somewhat greater than for the shortshaft, and the relative weight of the weighted cap is somewhat less, inorder to keep the overall combined weight of body and cap at a level ofaround 250 grams.

In accordance with one aspect of the invention, a plurality of optionalweights are provided, which can be used in various combinations, inconjunction with the weighted cap 24, in order to enable adjustment ofthe weight of the putter to suit a particular golfer's requirements. Ina preferred embodiment, three additional weights are provided,identified by the reference numerals 32, 33 and 34 (FIG. 1). Toadvantage, the optional weighs 32-34 are formed of the sametungsten-copper alloy as the weighted cap 24, and each is of a differentweight. For example, the weight 32 may weigh 15 grams, the weight 33 mayweigh 25 grams, and the weight 34 may weigh 35 grams. Each of theoptional weights is in the form of a flat disc, of a diameter to beclosely accommodated within the cylindrical recess 22, as reflected inFIG. 3, and each is provided with a central threaded opening 35,enabling the disc to be threaded on to the shaft 25. The shaft 25 isthreaded as close as practical to the end surface 36 of the weightedcap, and a small undercut 37 is provided adjacent the surface 36 toallow a weight to be threaded on to the shaft into tight abuttingrelation to the end surface 36 of the cap 24 (see FIG. 5). The optionalweights 32-34 can be omitted or used in any combination of one, two orthree with the cap 24. Altogether, this provides for eight differentweighting possibilities (the end cap alone (1), each wieght by itself(3), each weight with one of the others (3), and all three weightstogether (1). In all cases, it is preferred that all of the discsutilized be advanced on the threaded shaft 25 as far as possible towardthe weighted cap 24, and into tight contact therewith, such that the capand optional weights function to concentrate their combined weight asfar back in the putter as practicable and also so that the weightsremain reliably fixed in their intended positions.

The invention provides a unique and advantageous adjustable weightputter, which not only provides for a wide variety of weightingadjustments to suit the desires of the golfer, but also assures aconcentration of weight as far behind the ball-striking face as ispracticable. The design of the putter body and weighted end cap is suchthat the weighted end cap forms the back surface extremity of theputter, thus assuring that its weight is located as far to the back ofthe putter as is practicable. The putter body is provided with arelatively deep longitudinally extending recess, opening at the back, inwhich the weighted end cap is received, serving to close and seal therecess. The end cap is formed with a forwardly extending threaded shaft,engaging a threaded recess extension in the putter body, and which alsoreceives optional weighted discs in various combinations. The weighteddiscs are threadedly received on the shaft and rotated until tightlyabutted as far back on the shaft as possible, again providing that theconcentration of added weight is located as far to the back of theputter as practicable. Both the weighted cap and the optional discweights are advantageously formed of a very high specific gravitymaterial, such as a tungsten-copper alloy, which has a specific gravitymore than six times that of an aluminum body.

By locating weight as far behind the ball-striking face as practicable,the putter head is given a high moment of inertia against rotation abouta vertical axis. This imparts resistance against rotation when a ball isstruck slightly off of the center line of the putter, resulting ingreater accuracy in the putting stroke.

It should be understood, of course, that the specific forms of theinvention herein illustrated and described are intended to berepresentative only, as certain changes may be made therein withoutdeparting from the clear teachings of the disclosure. Accordingly,reference should be made to the following appended claims in determiningthe full scope of the invention.

1. An adjustable weight golf putter which comprises (a) a putter headhaving a ball-striking face of predetermined width and a body portionextending rearwardly from said striking face for a distance equal to asubstantial fraction of said predetermined width, (b) said body portionbeing formed of a relatively low specific gravity material and having alongitudinal axis disposed in perpendicular relation to saidball-striking face, (c) said body portion having a cylindrical recesstherein, open at a back extremity of said body portion and extendingforwardly therein along said longitudinal axis, (d) a weighted cap,formed of a material of substantially greater specific gravity than saidbody portion, received in back extremities of said cylindrical recessand closing said recess, (e) said weighted cap having a threaded shaftfixed to a forward end thereof and extending forwardly therefrom alongsaid axis, (f) said body portion having a recess extension therein at aforward end of said cylindrical recess for closely receiving andconfining a forward end portion of said threaded shaft, (g) one or moredisc-like weights having a diametrical dimension to be closely receivedwithin said cylindrical recess and each having a central threadedopening for selective threaded reception on said threaded shaft, (h)said disc-like weights being formed of a material of substantiallygreater specific gravity than said body portion and being positioned insubstantially abutting relation to said weighted cap.
 2. An adjustableweight golf putter according to claim 1, wherein (a) said recessextension is threaded to receive the forward end of said threaded shaft,and (b) said weighted cap is held in its installed position by saidthreaded shaft.
 3. An adjustable weight golf putter according to claim1, wherein (a) said weighted cap has a weight in excess of 20% of thecombined weight of said body portion and said ball-striking face.
 4. Anadjustable weight golf putter according to claim 1, wherein (a) said oneor more disc-like weights comprising at least two such weights, each ofa different weight, whereby combinations of one or more of said weightswith said weighted cap provide a variety of weight balances for saidputter.
 5. An adjustable weight golf putter according to claim 1,wherein (a) said body portion is formed primarily of aluminum and saidweighted cap is formed primarily of a tungsten copper alloy.
 6. Anadjustable weight golf putter according to claim 5, wherein (a) saidtungsten copper alloy has a specific gravity of about
 17. 7. Anadjustable weight golf putter according to claim 1, wherein (a) saidweighted cap is formed with an enlargement at a back extremity thereof,and (b) said cylindrical recess is formed with an enlarged open endportion for reception of said enlargement, for positioning said weightedcap and sealing said cylindrical recess.
 8. An adjustable weight golfputter according to claim 7, wherein (a) back portions of said bodyportion are arcuately contoured, and (b) said weighted cap has arearwardly facing surface contoured to correspond with the contouredback portions of said body portion and form a generally smoothcontinuation of the contours of said back portions.
 9. An adjustableweight golf putter which comprises (a) a putter head having aball-striking face of predetermined width and a stem portion extendingrearwardly from said ball-striking face at right angles thereto, (b)said stem portion having a longitudinal axis intersecting saidball-striking face in a central portion thereof and having a widthsubstantially less than the width of said ball-striking face, (c) a bodyend portion joined with a rearward portion of said stem portion andextending rearwardly therefrom, (d) said body end portion having a widthgreater then the width of said stem portion and less than the width ofsaid ball-striking face, (e) said body end portion having a cylindricalrecess therein, open at a back extremity of said body end portion andextending forwardly therein along said longitudinal axis, (f) a weightedcap, formed of a material of substantially greater specific gravity thansaid stem and body end portions, received in back extremities of saidcylindrical recess and closing said recess, (g) said weighted cap havinga threaded shaft fixed to a forward end thereof and extending forwardlytherefrom along said axis, (h) one of said body end portion and saidstem portion having a recess extension therein at a forward end of saidcylindrical recess, (i) said recess extension being threaded forengagement with a forward end portion of said threaded shaft forsecuring said weighted cap in said body end portion, (j) said weightedcap having a weight of at least about 20% of the combined weight of saidball-striking face, said stem portion and said body end portion.
 10. Anadjustable weight golf putter according to claim 9, wherein (a) one ormore disc-like weights are provided, each having a diametrical dimensionto be closely received within said cylindrical recess and each having acentral threaded opening for threaded reception on said threaded shaft,(b) said shaft being threaded to a point closely adjacent a front faceof said weighted cap, whereby one of said weights may be positioned inabutting relation to said front face.
 11. An adjustable weight golfputter according to claim 10, wherein (a) at least three such disc-likeweights are provided, each having a different weight, wherebycombinations of some, all or none of said weights may be selectivelymounted on said threaded shaft to provide a variety of weight balancesfor said putter.
 12. An adjustable weight golf putter according to claim11, wherein (a) said weighted cap and said disc-like weights are formedof a tungsten-copper alloy having a specific gravity of about
 17. 13. Anadjustable weight golf putter according to claim 12, wherein (a) saidstem and body end portions of said putter head being formed of aluminum.14. An adjustable weight golf putter according to claim 9, wherein (a)said cylindrical recess is formed with an rearwardly divergent taperedentrance recess at the back extremity of said body end portion, and (b)said weighted cap has a cylindrical forward portion, closely received insaid cylindrical recess, and an rearwardly divergent collar at arearward end thereof, (c) said rearwardly divergent collar beingreceived in said tapered entrance recess to position said weighted capand to seal said recess.
 15. An adjustable weight golf putter accordingto claim 9, wherein (a) said putter head is formed with integral,rearwardly tapered gussets extending from said ball-striking face tosaid body end portion along each side of said stem portion, (b) saidgussets having a thickness substantially less than said ball-strikingface, said stem portion and said body end portion.
 16. An adjustableweight golf putter according to claim 15, wherein (a) said body endportion is formed with convexly arcuate back face contours, (b) saidweighted cap is formed with a convexly contoured back face, and (c) saidweighted cap is positioned by said rearwardly divergent recess andcollar such that the contoured back face of said cap forms acontinuation of the contours of said body end portion.
 17. An adjustableweight golf putter according to claim 15, wherein (a) said gussets arealigned generally in a horizontal plane including said longitudinalaxis.
 18. An adjustable weight golf putter according to claim 9, wherein(a) said putter head is of predetermined length, and (b) the respectiveweights of said putter head and said weighted cap are such that thecenter of gravity of the combined putter head and weighted cap is spacedbehind said ball-striking face a distance which is more than half ofsaid predetermined length.